package com.skwyb.form.utils;

import com.skwyb.form.constants.ResultCode;
import com.skwyb.form.core.BusinessException;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.http.HttpSession;
import org.springframework.util.Base64Utils;

public class Captcha {

    private static char mapTable[] = {
        '0', '1', '2', '3', '4', '5',
        '6', '7', '8', '9', '0', '1',
        '2', '3', '4', '5', '6', '7',
        '8', '9'};

    public static Map<String, Object> getImageCode(int width, int height) {
        Map<String, Object> returnMap = new HashMap<String, Object>();
        if (width <= 0) {
            width = 60;
        }
        if (height <= 0) {
            height = 20;
        }
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        // 获取图形上下文
        Graphics g = image.getGraphics();
        //生成随机类
        Random random = new Random();
        // 设定背景色
        g.setColor(getRandColor(200, 250));
        g.fillRect(0, 0, width, height);
        //设定字体
        g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
        // 随机产生168条干扰线，使图象中的认证码不易被其它程序探测到
        g.setColor(getRandColor(160, 200));
        for (int i = 0; i < 168; i++) {
            int x = random.nextInt(width);
            int y = random.nextInt(height);
            int xl = random.nextInt(12);
            int yl = random.nextInt(12);
            g.drawLine(x, y, x + xl, y + yl);
        }
        //取随机产生的码
        String strEnsure = "";
        //4代表4位验证码,如果要生成更多位的认证码,则加大数值
        for (int i = 0; i < 4; ++i) {
            strEnsure += mapTable[(int) (mapTable.length * Math.random())];
            // 将认证码显示到图象中
            g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
            // 直接生成
            String str = strEnsure.substring(i, i + 1);
            // 设置随便码在背景图图片上的位置
            g.drawString(str, 13 * i + 20, 25);
        }
        // 释放图形上下文
        g.dispose();
        returnMap.put("image", image);
        returnMap.put("strEnsure", strEnsure);
        return returnMap;
    }

    //给定范围获得随机颜色
    static Color getRandColor(int fc, int bc) {
        Random random = new Random();
        if (fc > 255) {
            fc = 255;
        }
        if (bc > 255) {
            bc = 255;
        }
        int r = fc + random.nextInt(bc - fc);
        int g = fc + random.nextInt(bc - fc);
        int b = fc + random.nextInt(bc - fc);
        return new Color(r, g, b);
    }

    public static String getBase64Img(BufferedImage bi) {
        String png_base64 = "";
        ByteArrayOutputStream baos = new ByteArrayOutputStream();//io流
        try {
            ImageIO.write(bi, "jpg", baos);//写入流中
            byte[] bytes = baos.toByteArray();//转换成字节
            png_base64 = Base64Utils.encodeToString(bytes).trim();//转换成base64串
            png_base64 = png_base64.replaceAll("\n", "").replaceAll("\r", "");//删除 \r\n
            png_base64 = "data:image/jpg;base64," + png_base64;
            baos.flush();
            baos.close();
        } catch (IOException e) {
            e.printStackTrace();
            return "";
        }

        return png_base64;
    }

    /**
     * 校验验证码是否正确
     *
     * @param code    验证码
     * @param session session
     * @throws BusinessException
     */
    public static void verify(String code, HttpSession session) throws BusinessException {
        // 获得验证码对象
        Object cko = session.getAttribute("simpleCaptcha");
        if (cko == null) {
            throw new BusinessException(ResultCode.VERIFY_CODE_ERROR);
        }
        String captcha = cko.toString();
        // 判断验证码输入是否正确
        if (!code.equalsIgnoreCase(captcha)) {
            throw new BusinessException(ResultCode.VERIFY_CODE_ERROR);
        }
        // 验证码有效时长为1分钟
        Date now = new Date();
        Long codeTime = Long.valueOf(session.getAttribute("codeTime") + "");
        if ((now.getTime() - codeTime) / 1000 > 60) {
            throw new BusinessException(ResultCode.VERIFY_CODE_TIME_OUT);
        }
        session.setAttribute("simpleCaptcha", null);
    }
}
